Improvement in let-offs for looms



UNITED STATES PATENT OFFICE.

JOB PHILLIPS, OF PA'WTUOKET, RHODE ISLAND.

IMPROVEMENT IN LET-OFFS FOR LOOMS.

Specification forming part of Letters Patent No. 50,156, dated September 26, 1865.

To all 'whom it may concern.-

Be it known that I, J 0B PHILLIPS, of Pawtucket, in the county of Providence and State of .Rhode Island, have invented a new and useful Improvement in Looms; and I do hereby declare that the following is a full, clear, and eX- act description of the construction and operation thereof, taken in connection with the accompanying drawings, making a part ot this specification, in which- Figure l is an elevation of a portion of the back side ot" a loom with myimprovement applied thereto. Fig. 2 is a plan of the same; and Fig. 3 is a transverse longitudinal section ot the same parts, looking outward.

The subject-matter of my invention relates to the Inechanism for letting off the warp from the yarn-beam as it is woven, and is an improvement in that class of letoif motions,77 so called, in which the delivery of the warp is controlled by the shortening of its length between the yarn-beam and the point where the cloth is made, which shortening of the warp causes the mechanism that unwinds the same from the yarn-beam to be put in operation in such a manner that the required length ot' warp is preserved.

In this class of let-ott'motions ausual mode ot' construction is to have the horizontal part ot the warp supported at the back side of the loom uponamovable whip-roll,77 so called, or some other equivalent support,the movement of which by the shortening otl the warp controls the action of the letting-oft' mechanism by sliding a shoe or shield, which is interposed between the ratchet-wheel which moves the yarn-beam and its pawl, so as to cause it to take a greater or less number otl teeth ot' the ratchet, and thus cause a greater or less delivery ot the warp at each pick, according to the amount required by the weaving.

My improvement consists in combining with a vibrating bar, used as a support for the warps at the back side of the loom, a long arm rigidly attached thereto, which extends downward, and the lower end ot' which engages directly with the shield upon the ratchet without any intermediate mechanism, so that a very small movement of' the vibrating bar will produce a great movement ofthe shield. By this means the control of the delivery is much more delicate than is possible whereintermediate levers and other parts are interposed between the whip-roll and the shield, as has been heretofore done.

In the drawings the letters refer to the same parts in all the figures.

A is the frameof the loom; B,theyarnbeam C, a worm-gear upon it; D, a worm upon the vertical shaft D', which engages with the gear G. Eis a ratchet upon the same shaft by which it is turned. F is a rocker-arm working loosely upon the shaft D', which receives a reciprocating motion from the lay by means ot' the rod F', and carries the pawl Gr, which works in the ratchet E. H is a shield or shoe, ofthe form shown, which is also mounted loosely on the shaft D', and is interposed between the ratchet and pawl, and by its position determines the number of teeth of the ratchet that the pawl shall take. All these parts are constructed substantially in the usual manner.

At the opposite side of the 'ulcrum ot' the shoe there is an arm extending outward, which engages with the lower end of the pendent arm l, which is rigidly attached to the axis of the vibrating bar J, which takes the place of a whip-roll. This vibrating bar J is of the form shown, and upon it the warp rests at two points, a and b. rI he point a is near the center of motion, and the point b extended with an upward inclination toward the lay. The warp is led over them, as shown by the red lines. By this arrangement it will be seen that a very small change in the length of the warp causes a great movement ot the shield H, and a great change corresponding thereto in the rate of delivery of the warp. The proper tension of the warp is preserved by means of the weight M, acting through the arm J', rod K, and lever Lin aperfectly-obvious manner.

In allthe let-0E motions oi'- this general character heretofore constructed oi' which I have any knowledge there has been interposed between the whip-roll or its equivalent and the shield H a series of rods and levers or other moving parts jointed together, the friction of which joints would oppose considerable resistance to movement, and the looseness of which would deprive the mechanism of that precision of movement which is desirable in all cases, and which in this case, where great sensitiveness and nicety of regulation are de- Combining the vibrating bar J with the signed to be obtained, are indispensable, bei shield H by means of the arm I, rigidly ati cause7 from the great leverage that the shield tached to the bar, all constructed and arhas in proportion to that of the vibrating bar, ranged as described.

and from the elasticity of the Warp, any con- Executed at Boston, July 15, A. D. 1865.

siderable obstacle to the free movement of tl1e y JOB PHILLIPS.

parts would prevent lts successful operation.

Having thus described my invention, what Witnesses: T claim as new, and desire to secure by Let- WM. C. HIBBARD, ters Patent, is- N. C. LOMBARD. 

